A significant problem in the study of human oral communication concerns how we utilize various types of sensory feedback in controlling the complexly patterned muscle contractions required for speech production. The general goal of this research is to advance our basic understanding of how auditory and perioral receptor information is utilized in the motor control of lip movements of speech. This problem is being studied by unpredictably stimulating the auditory and perioral systems during various lip muscle conditions. The analysis of electromyographic and movement data in terms of the magnitude and latency of any reflexive or compensatory responses should provide significant insight into the central processing of sensory information during speech production. This should in turn contribute to the development of speech production models having significant utility for the diagnosis and treatment of various speech disorders.